Spark-plug.



G. L`. BREWER.'l

' SPARK RLUG. APPLICATION FILED APR. 8..'1QI9. v 11,321,710. PatentedNov. 11,1919.

.l1 llllllllll V- tion throughfthe'spark. plugi; and Fig. 3 is it andthe lower tubular. part of the sleeve.

To all-whmm 'of which thefollowing-is a speeification.

'base .2 projridgdfwit -by an inclinedshouler', and having upper end.

very thin.. Tlie'bottom end 8 of the sleeveis -beveled or inclined in'the reverse cylindrical, and it has -a cylindrical cover or MICHIGAN.

i'sranir-PLUG.

y. L. i -.tery or source of electricity. This bar elec; -Be itknwnthatffl, GOVE'RNR ""trode extends crosswise .under the end o 1 acitzen'off theUnited State'sfresiding at the glower electrode member 21,and'its mid Kent ,CityJnthe'` county of Kent.' and State dlepart iscurved upwardly so as to forman of Michigan, havev invented certainnew'. "ignition spark gap ,withthe end of the lower '6 0 and usefulImprovements in Spark-Plugs, ,electrode member 21.' The spark-isfanshaped d is localized at' the middle part of Th'isinvention`re1ates'-to -sparkplugsfori-thecrossbar by this'construction.

'use -in 'connectionfwith' internal cmbustion nup'per plug 26 ofinsulatingmaterial i engines and other purposes; it'consists ls.prov1ded, and' has a circumferential 6 inzthe.novelfconstructiom andcombination r 7grto'ine'27 atits middle'part. The' plug 26 of-th'epartshgregnafter fully dscribed and, 1s 1nserteil in the upper endportion ofthe claimed. Y .r1 6, and the top portion of the sleeve Inthedra irigs, Eigure 1 is-a side view g iscjrlmped-gr bent into engagementwith the. ofthe spark gplug. Eig. v2 is a. vertical sec-j grr 1i"ove 27-so asto hold the plug '26 in fplace.

upper plug 26'has ashoulder 23' at its a ian view of the same, frombelow.'` gflo'wer end."and a projection 29. A A.short he sparkfplug hsie tubi'ilaij.supportingY "sight tu'be 3010i glass or other transparentiff screwthreadedfporfmaterial is vinserted in the sleeve between tion'3 for i cojncfting ittoth'e'- cylinder Ao f fthe-two 'plugs beforetheupper plug; is se- "le" the en'gine or etlfer object'to whichit is to:.ured in place, and is held in place between be attached; The'upperfpaxft @f the base the shoulders'lf) and 28. The projections has.a chamber 4:* connectd' to the tubular^v 2 0 and 29 projectY a littleinto the'end por- '.,tions of this-siglit tube. By crimping or 'bendingthethm upper end of the sleeve -80 the glass sighttube can'be secured inposi-,

A tubular sl'eeve` 6 is provided and has a tlon' without breaking it.Sight tubes arev screwthreaded lower end portion 7 which is' easlly-broken when-secured between screwscrewed into the upper part of thebase; vthreaded portions. i The upper end portiom of 'this sleeve istapered externally -so that its top edge is aninternallyscrewtheadedportion at its or is 'otherwise secured into the upper plug26 so as `to be adjustable longitudinally in it, .and its lower' end-.=.forms a spark g'p'with -the .upper end of the lower electrode member .z21. Sight openings 33 are formed onoppo- 90 site sides of the sleeveopposite this sparkgap so that the working of' the .devicemmb' l,bevisible. The upper end portion'. of'fthe" electrode member 32 projectsfrom the'upper. .plug. 26, and is providedl with'a lock nut Q5 thecollar'12 and the sleeve and the shoulder 34 and a clamping nut .35 forthe wire L36' respectively, and the upper washer has a; which conductsthe electricity to. the'i'ifgei? downwardly projecting flange 16 Whichjvfdffvd:The. 0tl1 e rele :tric,wileift overlaps the cylindrical part ofthe collar. .l nested with tli .base of the plug in th" usual The upperend portion 417 of the plug is 'direction to the shoulder 5 bnthe base.

A main plug 10 of insulatingmaterial 1s arranged in the base andsleeve;and 'it has an enlargement or. collar 12 which is aI-, ranged .inthe chamber 4 between the end o f the sleeve land the shoulder on 'thebaser Washers 14 and 15 are 'interposed between or shield 18 of asbestosinterposed between made of asbestos, or are lined with asbes t The upperend portion ofthe plughas a shoulder 19 and a` projection 20.v

The lower`electrode membe 21 is secured centrally in the plug 10with'its ends projecting therefrom.' A bar 'electrode 24 is secured tothe bottom end of the base, and is connected to one pole of any approvedbatsure inthe lower cylinder, and prevent.. the-12'4 An upper electrodemember 32 is screwed f85 way to form acircuit through the device. 10 Thewashers '14.'and 15 are preferably" Theymake gas tight joints againstthe pres'f main plug lfrom getting chipped and brolen. '105. .Theasbestos cylinder 18 also preserves the secured thereto', a, cylndrcul'liner of asbes-A tos in the lower part of the sleeve, a mai 4 plug'of.lnsulatmg material'secured between the buse and sleeve with its upperendpro- 5 jecting through the said liner, an upper plug ofinsultingmaterial seured in the upper v end of the sleeve, and electrodes carriedby the two said plugsl and forming araux-ilimjy spark gap. 'f *Y Intestimony whereof I have axed my ,10'

signature. A

v GOVERNOR L. BREWER.

